Many bags, envelope-, and pouch-type packages are disclosed in the patent literature. Those patented packages thought to most closely resemble the novel, leakproof containers disclosed herein are illustrated and described in the following United States patents.
______________________________________ U.S. Pat. No. Patentee(s) Issue Date ______________________________________ 2,819,010 Amiguet 07 Jan. 1958 3,070,280 Richmond 25 Dec. 1962 3,310,225 Hoblit et al. 21 Mar. 1967 3,372,861 Johnson et al. 12 Mar. 1968 3,613,874 Miller 19 Oct. 1971 4,348,440 Kriozere 07 Sep. 1982 4,580,683 Gochenour 08 Apr. 1986 4,759,643 Canno 26 July 1988 4,785,940 Wilson 22 Nov. 1988 ______________________________________
Packaging or containers of the type with which the present invention is concerned have front and back walls sealed together or otherwise integrated at the sides and bottom of the container and a flap for closing the remaining, open end of the container. This flap is typically an integral part of the container rear wall or bonded at one edge to that wall. Once the wanted contents have been loaded into the container, the flap is folded down over the open end of the container to close that end and bonded to the container's front wall.
For the container to not leak, the seal or seam between the back and front walls of the container must have total integrity over the entire length of the container. While a seal of that character can easily be realized in the more central positions of the container, this goal is difficult to reach those ends of the side margins of the container at its open end. Consequently, fluids--albeit in small or even minute quantities--may escape at their marginal edges from the interiors of bags in which fluids have heretofore been transported or stored. Because these fluids may be contaminated with deadly toxins, viruses, etc., even minute leakage of the fluid is unacceptable.
Because their contents may be dangerous, it is often imperative that the closure of a container employed to transport or store fluids be tamper evidencing. This means that attempts to open and then reseal the container must be made readily apparent.
Of those patents cited above, only Amiguet (U.S. Pat. No. 2,819,010) appears to be concerned with the problem of leakage of a fluid from the interior of a container to the surrounding environment. However, the Amiguet closure system does not address the problem of increased susceptibility to leakage at the edges of the bag; and, at those locations, his closure-to-container seal is structurally conventional and would be no more resistant to leakage than a conventional one.
As is made apparent in parent patent application Ser. No. 07/575,064, containers with tamper evidencing closure systems are not only known but are widely used in applications involving the transfer of currency, stock certificates, bearer bonds, and other valuable items. However, no one has heretofore to my knowledge addressed the problem of furnishing a system which is capable of both providing an absolutely liquidtight seal and evidence of tampering.